Apparatus for simultaneously transmitting and receiving space-telegraph signals.



N0. 7I.6,|-346. Patented Dec. I6, I902.

J. S. STONE. APPARATUS FOR SIMULTANEOUSLY TRANSMITTING AND RECEIVING SPACE TELEGRAPH SIGNALS.

(Application filed Jan. 23, 1901. Renewed Feb. 24, 1902.)

(No Model.)

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JOHN STONE sToNE, oFBosToN, MASSACHUSETTS, AssIo oR TO LoUIs E. WHICHER,'ALEXANDER P. BROWNE, AND BBAINERD T. JUDKINS,

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srnomca'rrox forming part of Letters Patent No. 716,136, dated December 16, 1902. Application filed January as, 1901. w s February 24, 1902. 7 Serial No. 96,198. (No model.)

15311 whom it my concern.-

Be it known that I, JOHN STONE STO E, a

citizen of the United States, residing at Boston; in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Apparatus for Simultaneously Transmitting and Receiving Space- Telegraph Signals, of which the following is a specification.

My invention relates to the art of signaling electrically between stations not connected by a conducting-wire, sometimes called 'space telegraphy, and more particularly to'the system of spacetelegraphy in which the signals are transmitted bymeans of unguided electromagnetic waves emanating from elevated conductors. For convenience this latter system shall hereinafter be designated as the elevated-conductor system of space tolegraphy to distinguish it from other systems of signalingelectricallybetween stations .not connected by a conducting-wire.

- If in the elevated-conductorsystem of space telegraphy as at present practiced a receiving-station be placed in the immediate neighborhood of-a transmitting-station, the receiving apparatus of the receiver-station is affected by signals from the transmitting-station. The result of this fact is that a receiv- .-,ing-station placed in theimmediate neighborhood of a transmitter-station is rendered useloss while the transmitting-station is sending signals, and a message from a remote transmitting-stati'ou will not be intelligently received at the receiving-station while a message is being transmitted from the neighboring transmitting-station.

The object of the present invention is to supply apparatus whereby a receiver and transmitter station placed in close proximity to one another may be operated simultaneously, the transmitter-station sending signals to a distant receivemstation and the receiverstation receiving intelligible signals-from a distanttransmitting-station without interferonce by the signals sent out from the neighboring transmitting-station.

The phenomenon upon which the present invention depends for its operation is one which is the electrical analogue of the pho: 5o.

nomenon of interference in sound and light. It may be illustrated most simply as follows: If two similar vertical transmitting-conductors have developedin them electric oscillations equal in amplitude and opposite in phase, electromagnetic waves will emanate fromeach, and at all points equally distant from the two vertical conductors these waves will be equal and opposite. Such points lie in a vertical planeequidistant between the which .will be unaffected by the oscillations developed in the two transmitting-conductors.

Careful consideration will show that more than two vertically-elevated transmitting-condoctors may be used provided the amplitudes and phases of their oscillations be properly chosen, with the result that planes or lines of interference are developed, and several verti- (sally-elevated receiver-conductors. may be placed in these planes or lines of interference. The receiver-conductors will then be unaffected by the oscillation in the transmittingconductors. I prefer to so place the trans- 8o mitting-conductors that the resulting electromagnetic waves are most powerful in the direction of the receiving-station with which it is desired to communicate. For example, if

two vertical transmitter-conductors are employed whose oscillations are equal in amplitude and opposite in phase'I prefer to place them half a complete wave length apart and in a vertical plane, including the vertical conductorof the distant receiving-station with 0 which it is desired to communicate, so that waves emanating from the two vertical conductors of the transmitting-stations shall reinforce each other in this particular direction.

When it is desiredto communicate with receiverstations in difierent directions from the transmitter-station, I mount the receiver and transmitter conductors upon a rigid.

We may therefore place in this vertical 6'5 plane, which we shall call the plane of in- 'terference, vertical receiving conductors frame capable of being rotated about a vertical axis and rotate the frame until the plane of the transmitter-conductors includes the vertical conductor of the particular receiverstation with which it is desired to communicate. If two vertical transmitter-conductors are employed in which the oscillations developed are equal both in amplitude and phase and it they be placed at a complete wave length apart, then also will there be vertical planes of interference half-way between them in which may be erected vertical receiver conductors which will be unaffected by the oscillations in the transmitter-conductors.

The figure illustrates an embodiment of the invention.

In the figure,V V V" are vertical wires. G is the ground. M, M, M, and M are inductioncoils. Cisacondenser. B isa battery. Risa relay. K is a coherer, and a is a generator of vibratorycurrents. The generatora. is shown diagrammatically and is intended to represent any generator of vibratory currents suitable for use in an elevated-conductor system of wireless telegraphy, the preferable form being that in each by the use of a spark-coil an oscillatory discharge of a condenser is obtained-such generators, fol-instance, as have been employed in high frequency experiments, notably by Nikola Tesla and Elihu Thomson. If in this organization it be determined to employ in V and V electric vibrations equal both in amplitude and phase, the wires V and V are placed a complete wave length or a multiple of a complete wave.

length apart; but if it be determined to employ in V and V" electric vibrations equal in amplitude and opposite in phase then the wires Vand V" are placed half a wave length apart or an odd multiple of half awavc length apart. The question as to whether the phases of the vibrations in V and V" will be the same or opposite is determined by the direction of the windings of the coils M and M in the usual way. In the operation of this organization the generator 0 develops electric vibrations, which are communicated, through the intermediary of the coil M, to the coils M and M" and thence to the vertical wires V and V". The oscillations thereby produced in the wires V and V" develop electromagnetic Waves which interfere in a vertical plane half-way between the vertical conductors; but they agree in phase to the right and left of the system, and therefore reinforce each other in these directions. Thevertical receiving-wire V is placed in the plane of interference and is therefore unaffected by the waves developed by V and V", whereas it receives the energy of waves from other transmitter-stations at a distance.

As regards the operation of the receiving apparatus associated with the elevated conductor V, electromagnetic signal-waves emana'ting from a distant transmitter-station and impinging upon this conductor develop therein electric vibrations which through the intermediary of the transformer-coil M are conveyed to the coherer K, which is thereby operated. The operation of the coherer permits the battery B to develop a current in the circuit D M K R of sufficient force to set in motion the relay R. The coherer K is acted upon by a decoherer, (not shown in the drawa ing,) which restores it to its normal condition of high resistance after the passage of each signal.

Having claim- 1. In a system of space telegraphy, means for transmitting and simultaneously or otherwise receiving sigual-waves comprising two vertical conductors, means for developing oscillations of equal amplitude in them, a vertical receiving conductor or conductors situated in the plane or line of interference of the waves emanating from said transmitting-conductors, and electric translating or receiving devices associated with said receiving elevated conductors, substantially as described.

2. In a system of space telegraphy, two grounded elevated transmitting-conductors, situated a distance apart equal to one-half the length of the wave to be transmitted, and means for simultaneously impressing on said conductors electric vibrations opposite in phase.

3. In a system of space telegraphy, two grounded elevated transmitting-conductors, situated a distance apart which bears a certain definite relation to the length of the wave to be transmitted, and means for simultaneously impressing on such conductors electric vibrations of a'certain predetermined phase relation.

4. In a system of space telegraphy, a plurality of grounded elevated transmitting-conductors, so situated with respect to the length of the electromagnetic waves to be transmitted, that waves radiated in the plane of said conductors are mutually reinforced, and means associated with said conductors for simultaneously impressing thereon electric vibrations whereby the radiation therefrom of the said waves is produced.

5. In a system for simultaneously transmitting and receiving electromagnetic signalfully described my invention, I

waves, two elevated transmitting-conductorswaves, means for generating a pluralitypfsets 1 30 of electromagnetic waves, and means for uentralizing the effect of said sets of electromagnetic waves upon a receiver situated at the ting means that it is unaffected by said transtransmitting-station. mitted waves, but is at thesame time respon- 1o 7. In a. system for simultaneously transsive to waves transmitted from another stamitting and receiving electromagnetic signa1- tion. v 5 waves, means for transmitting a plurality of JOHN STONE STONE.

sets of electromagnetic signal-waves from one In presence oftransmitting-station, and a receiving-conduc- ALEX. P. BROWNE,

tor so situated with respect to the transmit- ELLEN B. TOMLINSON. 

